1. FIELD OF THE INVENTION
This invention pertains to a socket tool used in conjunction with drivers for driving bolts, nuts, and the like and, more particularly, to a socket tool having a retaining device for keeping a received bolt, nut and the like in alignment with the axis of the socket of the socket tool independent of the orientation of the socket.
2. DESCRIPTION OF THE PRIOR ART
It is well known in the art to fasten together two or more structures by use of a bolt and nut combination, or other like fasteners, such as lag screws. The bolt, nut, and the like are provided with a multi-faced portion, typically of square or hexagonal shape, for interfacing with a complementary shaped socket of a socket tool.
There has been, and continues to be, a longstanding problem in the relevant art to devise a cost effective and reliable retainer device for bolts, nuts and the like, hereinafter referred to as multi-faced fasteners, with regard to the sockets of socket tools, such as those used in ratchet wrenches and automated machine tools. This problem has plagued the art because there must be a small amount of play between the surfaces of the multi-faced fastener and the socket in order to facilitate easy insertion and removal of the multi-faced fastener relative to the socket. As a result, there is frequently a tendency for the multi-faced fastener to fall entirely out of the socket in situations where the socket is oriented vertically downward, resulting in the multi-faced fastener depending from the socket. This situation is of great concern to a mechanic, since it can frequently result in the loss of the multi-faced fastener into an inaccessible location of the work piece. As a result further, there is frequently a tendency, when the multi-faced fastener is of male configuration, as represented by a bolt, lag screw or the like, for the male multi-faced fastener to droop out of axial alignment with the socket when the socket is oriented in other than a vertical orientation, especially a horizontal orientation. This situation can occur with female configured multi-faced fasteners, such as nuts, but to a lesser degree. Droop is of great concern to manufacturers and users of automated machinery incorporating automatic drivers because alignment of the multi-faced fastener relative to the socket in which it is received is critical with respect to trouble free threading of the multi-faced fastener into precisely located apertures of the components of a work piece undergoing assembly.
Many solutions to this problem have been devised in the prior art, each of which in some manner modify the socket to effect retention of the multi-faced fastener thereinto. These solutions fall into three broad categories: biased retainer devices which abut the faces of the multi-faced fastener, frictional spacer retainer devices which also abut the faces of a multi-faced fastener and, finally, retainer devices which overlappingly interfere above and below the multi-faced fastener.
The first class of retainer devices is represented by U.S. Pat. No. 2,805,594 to Fogel which teaches a wrench socket provided with a slot into which a folded projection protrudes thereinto. The folded projection is mounted on a resilient spring steel annular ring which slips over the periphery of the wall of the socket. When a multi-faced fastener is inserted into the socket, the folded projection biases against one face of the multi-faced fastener, causing it to be retained in the socket. Other examples of this class of retainer devices include: U.S. Pat. No. 2,953,049 to Vilmerding and British Pat. No. 211,036 to McCarthy which disclose biasing a multi-faced fastener by a plurality of face abutting spring biased spherical balls; U.S. Pat. No. 3,005,367 to Vose which discloses an annular resilient ring which biases face abutting spherical balls; and U.S. Pat. No. 3,142,211 to Faso which discloses a slotted socket around which a U-shaped spring steel retainer is located so as to contact a multi-faced fastener when it is received into the socket. This first class of retainer devices suffers from the disadvantage that a bolt received by one of these modified sockets can droop for certain orientations of the socket because the retainers used do not abut the faces of the bolt head along a line perpendicular to the axis of the socket, but rather abut the faces of the bolt head either only at a point location or along a line parallel with the axis of the socket.
The second class of retainer devices is represented by U.S. Pat. No. 3,630,107 to Carr which teaches a spring keeper having an annular ring portion for clipping onto the periphery of the socket and a U-shaped portion, a part of which is structured to protrude into the socket. The protruding part is located in a groove of the socket and presses against a face of an inserted multi-faced fastener. Other examples of this class of retainer devices include: French Pat. No. 996,686 which discloses frictional interference members on the walls of the socket; U.S. Pat. No. 2,634,641 to Hodges which discloses a slotted socket over which a flared sleeve is slid to secure a received multi-faced fastener; U.S. Pat. No. 3,665,791 to Carr which discloses a resilient wire keeper that has two extension members that insert into the socket; U.S. Pat. No. 3,835,737 to Carr which discloses a U-shaped head having a depending extension, the U-shaped head fitting into the blind end of the socket so that the extension can contact an inserted multi-faced fastener; and U.S. Pat. No. 4,060,113 to Matsushima which discloses a bow shaped spring which is inserted into a passage in the socket wall, a portion of which protrudes into the socket. The second class of retainer devices suffers from the disadvantage that by placing foreign objects into the socket, it is possible for jamming to occur, as well as interference with the proper operation of the socket with the multi-faced fastener. Additionally, excessive wear can be expected, since these devices involve considerable sliding friction when the multi-faced fastener is inserted and removed.
The third class of retainer devices is represented by U.S. Pat. No. 2,256,012 to Blair which discloses an automatic tool for supplying and driving female multi-faced fasteners. A first set of plungers at the forward end of the multi-faced fastener and a second set of plungers at the rearward end thereof provide for selection of which nut is currently available for use in a fastening operation. By this provision, a series of multi-faced fasteners can be held ready for use while the one which is currently in use is held in position by the first and second sets of plungers. Other examples of this class of retainer devices include: U.S. Pat. No. 1,655,168 to Speckman which discloses a wrench having a sliding retainer member which utilizes lip interference to hold the nut on the wrench; U.S. Pat. No. 2,631,485 to Stuart et al which discloses a plurality of jaw dogs that are jammed against the multi-faced fastener as it is inserted into the socket; U.S. Pat. No. 2,927,491 to Bochman, Jr. which discloses a magazine feed driver having retaining balls which coact with movement of a sleeve relative to a cam for regulating release of each multi-faced fastener; U.S. Pat. No. 3,379,231 to Gallo, Sr. which discloses a driving tool having a plurality of clamping jaws which hold a received multi-faced fastener in position for driving; U.S. Pat. No. 3,416,395 to Hanson which discloses a lug wrench that retains lugs in its barrel by action of spring biased balls; U.S. Pat. No. 3,707,894 to Stillwagon, Jr. which discloses cylindrical magnets used to grip a magnetizable multi-faced fastener and its washer; U.S. Pat. No. 3,808,918 to Carr which discloses a magnetic keeper retained at the blind end of a socket; and U.S. Pat. No. 4,474,090 to Berecz which discloses a nut feeding tool having nut regulation controlled by spherical balls moved by a sleeve in conjunction with a cam. This third class of retainer devices suffers from the disadvantage that it is not practical to utilize any form of projecting members which overlappingly interfere with the multi-faced fastener because this will correspondingly interfere with the insertion of the multi-faced fastener into the socket. Additionally, devices utilizing magnetism are undesirable because frequently it is required that the multi-faced fastener inserted into the socket not become magnetized and, further, frequently nylon or other non-magnetic types of multi-faced fasteners may be used, in which case a magnetic keeper is useless.
Accordingly, there continues to remain in the art the need to provide a simple, effective, reliable, and inexpensive socket retainer device for multi-faced fasteners which prevents both slipping and drooping of a received multi-faced fastener irrespective of the orientation of the socket, provides easy insertion and removal of the multi-faced fastener, and assures long life and excellent mechanical properties of the socket.